package com.explorati.map.leetCode349;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.Set;

/**
 * 349. Intersection of Two Arrays Input: nums1 = [1,2,2,1], nums2 = [2,2]
 * Output: [2]
 * 
 * Example 2: Input: nums1 = [4,9,5], nums2 = [9,4,9,8,4] Output: [9,4]
 * 
 * @author explorati
 *
 */
class Solution {
	public int[] intersection(int[] nums1, int[] nums2) {
		Set<Integer> set = new HashSet<Integer>();

		for (int num : nums1) {
			set.add(num);
		}

		ArrayList<Integer> list = new ArrayList<>();
		for (int num : nums2) {
			if (set.contains(num)) {
				list.add(num);
				// 找到之后就在集合中删除，这样就避免了重复元素contains多次
				set.remove(num);
			}
		}

		int[] res = new int[list.size()];
		for (int i = 0; i < res.length; i++) {
			res[i] = list.get(i);
		}
		return res;
	}
}
